Multiple choice Which of the following is a major constituent of connective tissues? Collagen Carbohydrate Lipid Cholesterol - Reveal answer Fill a bubble to check yourself A Correct answer Explanation Collagen is the main structural protein in the extracellular space of various connective tissues. As the main component of connective tissue, it is the most abundant protein in mammals and makes up to 25% to 35% of the whole-body protein content.